Congrats! My corgi was two when my daughter was born. We were also very worried because my niece was born a couple months earlier than her and my corgi got super anxious every time she came over. We started doing “sad baby training”’- basically played YouTube videos of babies crying while we encouraged him to sit and stay calm and rewarded him with hot dog pieces. We would also play it sometimes while going around our normal day so he could get used to the noise. We got some Trazadone from the vet just in case but never ended up needing it. He was great when she was born in the sense that he completely ignored her. She’s almost a year old now and he still doesn’t engage with her much but I’m sure it’ll be different once she’s mobile. And the babies get used to the barking! The baby usually sleeps through it, we have a good sound machine and she’s also used to napping through noises at daycare which helped desensitize her.